1. Field of the Invention
The present invention relates to the design of welding equipment, and particularly to devices for removing burrs in butt resistance welding by machines of the grip type.
The invention may prove most advantageous for butt resistance welding of pipes when laying main pipelines.
Arrangements for removing burrs in butt resistance welding are known for a comparatively long time. However, no arrangement for removing burrs has been developed up to now which ensures high quality of deburring under conditions of an increased productivity of the welding process when treating workpieces of various profiles, and particularly in butt resistance welding of pipes.
2. Prior Art
Known in the art are arrangements for removing burrs from welded butts of rails, pipes, shaped steel articles etc. (U.S. Pat. Nos. 3,081,673, 3,336,839, French Pat. No. 1417444, Japanese Pat. Nos. 46-8568 and 45-29092). The above arrangements comprise a system of deburring cutters whose cutting edges form a profile of the workpiece cross-section. Said cutters are operatively connected to a mechanism for pressing the cutters to the workpiece surface and to a drive for shifting them along the workpiece.
However, such an arrangement is disposed separately from the welding machine and cuts off burrs which have already cooled down, whereby the process capacity is significantly decreased.
The above disadvantage is eliminated to a large extent with an arrangement for removing burrs in butt resistance welding of rails (USSR Author's Certificate No. 697275). The above arrangement is mounted on one of movable bodies of a welding machine of the grip type, said body being at the same time the body of the given device. The arrangement comprises a body separable from the vertical axis of a workpiece and constructed as a grip clamp provided with two jaws coupled with each other in the upper portion thereof by a clamping cylinder, a cross member being fixed on the rod thereof. In the lower portion of said jaws are mounted one upper cutter and two side cutters whose cutting edges form a profile of the rail cross-section. The two side cutters are mounted on pivots, which are rigidly secured on said jaws. Said cutters are disposed symmetrically relative to the vertical axis of the rail.
The arrangement is provided with a mechanism for pressing the cutters to the rail surface. Said mechanism is made as a stop fixed on the cross member, said stop being operatively coupled with the upper cutter, which in turn is pivotally connected to the side cutters.
The above described arrangement ensures removing burrs from the welded butt over the whole perimeter of the rail immediately after the termination of the welding process. However, the above arrangement provides for a high quality of deburring and an increased capacity only when processing rails. In the utilization of said arrangement in the process of welding pipes, boxshaped articles and channel bars, the variation of location of the cutters in accordance with the profile of said workpieces does not ensure high quality of deburring.
The above fact is explained by the occurrence of deformation of said articles in the course of clamping them the body of the welding machine. As a result, the cutting edges of the cutters do not embrace the workpiece tightly over the perimeter thereof, and thereby a required space between the cutting edges of the cutters and the surface of a workpiece to be processed is not ensured. A decrease in the quality of deburring in turn results in the reduction of the capacity of the welding process. This fact can be explained by the need in an additional treatment of the weld.
Moreover, in the process of deformation of the workpiece surface (in the course of clamping) the deformation forces are taken by the cutters and are transmitted to pivots rigidly fixed on the jaws. As a result, the reliability of operation of the device is significantly lowered due to a possible damage of the above pivots. Thus, the above described arrangement can be effectively used only in the welding of rails, thereby considerably limiting the scope of working thereof.